This section provides background information related to the present disclosure that is not necessarily prior art. This section further provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.
Most current aircraft ice detection systems are based on measurements by ice-collecting probes, not placed directly on the areas where ice accumulation can cause problems. For example, U.S. Pat No. 7,104,502 is for a system capable of detecting the accumulation of ice by measuring changes in the vibration frequency of a strut mounted on the nose cone of an aircraft. The strut contains at least one feature that allows ice to accrete on it at higher rate than in other parts of the aircraft. U.S. Pat. No. 7,370,525 refers to a dual channel inflight system that detects ice accretion on a housing containing a light source, mounted on the aircraft surface. The system illuminates the housing with linearly polarized light. Light conductors with polarization sensitivity aligned to the transmitted light and with polarization sensitivity orthogonal to it acquire the backscattered light. The ratio of the intensities of the light in the two conductors is used to detect the presence of ice. The prior art systems described above detect ice on ice-collecting probes and housings, not directly on the places where ice accumulation can cause problems. Thus, they do not detect ice accumulation where it can be a hazard, such as on the air intake of pitot tubes, static ports, engines, wing surfaces and control surfaces.
The aircraft ice detection system of the present teachings comprises an electromagnetic microwave resonator capable of measuring the complex dielectric permittivity of ice accumulated on aircrafts surfaces, air intakes and engines core. In some embodiments, the system contains a multiple frequency microwave resonator, a data processor unit, and interfaces with flight displays and flight systems.
The present teachings provide, in part, a system capable of detecting the hazardous accumulation of ice on the surfaces, engines, instruments and air intakes of an aircraft or other objects of interest. Contrary to the previous art, the present system includes an electromagnetic microwave resonator capable of detecting the formation of ice directly where it could cause problems. The microwave resonator sensor can be mounted around the air intake of pitot tubes, static ports, on engines core, and can be embedded in the aircraft skin. The system uses algorithms based on the variations of the complex dielectric permittivity of water substance with frequency to distinguish the various types of ice from each other and from water. The system uses changes in the microwave resonant frequencies, their quality factors, and the transmitted and possibly received power to detect ice and to measure the ice thickness. The system is capable of determining the type and thickness of ice accumulated in the areas of interest as well as the rate of accumulation. In some embodiments, the system uses a dual frequency microwave resonator to distinguish water and the various types of ice from each other. A warning could be given when ice starts to accumulate. A hazards alert could be given when the thickness of the ice accumulated and/or the rate of accumulation reaches pre-established values regarded to be dangerous.
Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.